1. Field of the Invention
The present invention relates to engine clutches. In particular, the present invention relates to clutches driven by engines and used to operate devices, such as fans.
2. Background of the Related Art
Over time, engines have been developed to convert energy into a useable output for performing work. Such energy conversion may involve, for example, the conversion of fuel, electricity or other sources into kinetic energy to impart motion. The conversion process used to generate outputs typically creates heat that can result in detrimental effects, such as increased inefficiency, engine damage and/or other negative effects.
To address the detrimental effects associated with heat, engines have been provided with ventilation devices, such as radiators, fans, heat exchangers and/or other devices that are capable of removing heat and/or reducing the temperatures associated with the engine. Fluids, such as air, water, coolants and/or other sources, have been used with ventilation devices to remove heat. However, such ventilation devices typically draw power from the engine (directly or indirectly), thereby further reducing the efficiency of the engine.
Engines have also been provided with mechanisms for transmitting rotation between the engine and another device for performing various functions. For example, clutches have been used to transmit the rotation of a crank shaft of the engine to operate devices, such as transmission, brake and/or other devices. Some engine mechanisms have been used in connection with magneto-rheological (“MR”) fluids for performing various functions as described, for example, in U.S. Pat. No. 6,186,290. In particular, MR fluids have been used in connection with clutches as described in U.S. Pat. No. 6,318,531 and M. Benetti, E. Dragoni, and Reggio Emilia, Nonlinear Magnetic Analysis of Multi-plate Magnetorheological Brakes and Clutches, Excerpt from the Proceedings of the COMSOL Users Conference, p. 1-5 (2006) Milano. MR fluids have also been used in connection with engine fans as described, for example, in U.S. Pat. Nos. 7,364,025 and 6,932,917.
Despite the existing advancements in engine technology, there remains a need to provide engine clutches that reduce the power drain on the engine. It is desirable that such clutches be adjustable to meet to the needs of a desired operation. It is further desirable that such clutches and/or associated devices be compact and/or simplified. The present invention as described herein has been developed to address these needs.